The present invention relates to a design for fences which are preferably assembled in situ and more particularly, to a novel design and method of assembly which utilizes a punching operation for joining certain components thereof.
Fences are typically constructed employing conventional fasteners. However, conventional fasteners often distort the fastened components and further detract from the otherwise aesthetic appearance of the fence. In one technique, described in U.S. Pat. No. 5,660,378, issued Aug. 26, 1997 and assigned to the present invention, although conventional fasteners are eliminated, the pickets employed in the fence assembly require pre-punching and/or pre-drilling of openings to receive the inserts employed in the fence structure.
The present invention is characterized by comprising a design and method for assembling a fence which eliminates the need for conventional fasteners and pre-punched or pre-formed holes and is comprised of only three basic elements, namely, a plurality of pickets, one or more inserts and a channel-shaped rail associated with each insert.
The pickets, in one embodiment, are each inserted through an associated one of the openings in the rail. The insert is positioned immediately beneath one side of the rail and with its flat surface engaging associated flat surfaces of the pickets. A piercing tool, such as a punch, pierces an opening into the insert and the picket associated therewith forming at least one tab which tab projects into the picket, locking the insert to each of the pickets. The rails are then pushed down over the pickets and the insert until a cooperating projection on the rail snaps into position between a pair of projections on the insert, locking the rail in place. The rail completely covers the insert providing an aesthetically pleasing, finished appearance.
The side of the rail opposite the side engaging the insert is provided with a solid, integral rib at its free end to provide rigidity over its length and a continuous internal finger which prevents the rail from rotating over the tops of the pickets in applications where the pickets do not extend through the rail.
The components making up the fence may be extruded, rolled or machined of metal, plastic or wood.
The punch is formed of a material capable of respectively puncturing and then deforming the insert and pickets so that they lock together. No mandrel is required on the interior of the pickets, but one may be used if desired, for example, in applications where the punches into the pickets are made near the ends thereof. The punch causes one or more tabs (preferably two) to be formed from the pierced insert and to protrude into the picket, preventing the picket from easily sliding vertically or horizontally in relation to the insert independently of the rail. The punch has no moving parts, but may be mounted upon a press, if desired.
The advantages of the invention reside in the fact that among others, the fence has no visible fasteners and a clean and esthetically appealing exterior finish, the fence can not be easily disassembled, providing security and the rails and pickets have a smooth continuous appearance and are distortion free which distortion may typically occur in fences having the components thereof joined by conventional fastening means.
It is therefore one object of the present invention to provide a novel fence design and method for assembling such a fence in which the only tool required for assembly is a punch.
Still another object of the present invention is to provide a novel fence design which is comprised of three basic elements, namely, pickets, a rail and an insert joined to each picket by a simple punching operation and covered by a rail to provide a neat, esthetically appealing finished appearance.
Still another object of the present invention is to provide a novel three-piece fence design of the type described hereinabove and wherein the insert member is snap-fittingly received within the rail to provide a self-locking feature while eliminating the need for conventional fasteners.
Still another object of the present invention is to provide a novel method of fence assembly that prevents rattling noise between pickets and rails which would otherwise be present due to the loosening of conventional fasteners.